Endocrine Abstracts

The ratio of the glucuronidated epitestosterone (E) and testosterone (T), used in doping tests, is currently under question. The key enzyme involved in E metabolism is UGT2B7 in contrast to T which is mainly metabolised by UGT2B17. Previous results demonstrated that at very high concentrations E acts as a competitive inhibitor to UGT2B17. Similarly, the literature reports competitive inhibition of UGTs by NSAIDS and phenolics that are not substrates of UGT2B17. The aim of this...

Introduction: Low levels of vitamin D are associated with higher mortality in critically ill patients. Studies on vitamin D levels in adult burn patients and their influence on clinical outcomes are scarce. Therefore, vitamin D status following thermal injury is often overlooked as its clinical implications are poorly understood.Aim: To examine the relationship of major thermal injury on the vitamin D axis and the influence of ...

Reduced renal synthesis of 1,25-dihydroxyvitamin D (1,25(OH)2D) from 25-hydroxyvitamin D (25OHD) in end stage renal disease (ESRD) results in low serum 1,25(OH)2D. This appears to be due to reduced renal cell function and elevated serum fibroblast growth factor 23 (FGF23). Treatment strategies have therefore focussed on 1,25(OH)2D or its synthetic analogues, alfacalcidol or paricalcitol. However this overlooks 25-hydroxyv...

Introduction: Low levels of vitamin D are associated with higher mortality in critically ill patients. Studies on vitamin D levels in adult burn patients and their influence on clinical outcomes are scarce. Therefore, vitamin D status following thermal injury is often overlooked as its clinical implications are poorly understood.Aim: To examine the relationship of major thermal injury on the vitamin D axis and the influence of ...

Reduced renal synthesis of 1,25-dihydroxyvitamin D (1,25(OH)2D) from 25-hydroxyvitamin D (25OHD) in end stage renal disease (ESRD) results in low serum 1,25(OH)2D. This appears to be due to reduced renal cell function and elevated serum fibroblast growth factor 23 (FGF23). Treatment strategies have therefore focussed on 1,25(OH)2D or its synthetic analogues, alfacalcidol or paricalcitol. However this overlooks 25-hydroxyv...

Recent in-vitro studies have shown that vitamin D metabolites undergo conjugation reactions by sulfation and glucuronidation and may be important mechanisms for the inactivation, storage and excretion of analytes. However the circulating concentrations and clinical significance of phase II vitamin D conjugation is unclear as current analysis has almost exclusively been restricted to measuring their unconjugated metabolite forms. In this study we aimed to develop an analytical ...

Vitamin D exists as two forms; D3 (UV) and D2 (plant derived). Measuring the metabolite 25-hydroxyvitamin D (25OHD) is routinely applied in research and clinical laboratories to assess vitamin D status. The Institute of Medicine and Society for Endocrinology have previously set recommended vitamin D guidelines based on combined 25OHD3 and 25OHD2 serum concentrations. In order to achieve accurate quantitation of these metabolites, the respective C3 epimers must be separately qu...

Vitamin D-deficiency during pregnancy has been associated with increased complications of pregnancy including a high risk of pre-eclampsia (PET). Current analysis of vitamin D ‘status’ is based exclusively on analysis of maternal serum 25-hydroxyvitamin D3 (25(OH)D3), the circulating precursor form of vitamin D. We hypothesised that comprehensive profiling of vitamin D metabolites may provide a more accurate determination of vitamin D function i...

Although a complex metabolic pathway for vitamin D exists, serum measurement of inactive 25-hydroxyvitamin D3 (25OHD3) continues to be the most common determinant of vitamin D ‘status’. However, several other metabolites contribute to the physiological role of vitamin D, notably the active form 1α,25-dihydroxyvitamin D (1α,25(OH)2D3), inactive 3-epi-25OHD3 and chiral 23R and 24R,25(OH)2D3 metabolites. Quantification of these additional metabolites could pro...

Idiopathic intracranial hypertension (IIH) is a condition of unknown aetiology characterised by raised intracranial pressure, chronic headaches and blindness. Akin to polycystic ovary syndrome (PCOS), IIH patients are almost exclusively obese females of reproductive age. A distinct androgen excess profile has been noted in PCOS. Here, we aimed to delineate androgen metabolism in IIH compared to PCOS and simple obesity.Women w...